Can for filling with hot goods



K. M. JACOBSEN CAN FOR FILLING WITH HOT GOODS Sept. 10, 1968 2Sheets-Sheet 1 Filed Jan. 18, 1965 INVENTOR KJELL M. JAcoBsEu Sept. 10,1968 K. M. JACOBSEN 3,400,353

CAN FOR FILLING WITH HOT GOODS Filed Jan. 18, 1965 2 Sheets-Sheet 2 FIG.3

INVENTOR KJELL M. JAcoBsEM BY I M will, W ATTOR M United States Patent3,400,853 CAN FOR FILLING WITH HOT GOODS Kjell Mosvoll Jacobson, Hohog,Sweden, assignor to AB Platmanufakter, Malmo, Sweden Filed Jan. 18,1965, Ser. No. 426,129

13 Claims. (Cl. 22066) ABSTRACT OF THE DISCLOSURE The present inventionrelates generally to can structures to be employed in packaging, andmore particularly to cans intended for use in the packaging of hotgoods. The can complement comprising a body, a top end closure closingone end of the body and a bottom end closure closing the other end ofthe body. Each said end closure of the can body having the quality ofassuming a convex or concave position depending upon differentialpressure application thereon internally and externally of the can.

It has been common practice to fill cans with cold goods. Such cans areclosed by seaming on or otherwise securing closures at each end, whichclosures have the quality or adaptability of assuming two differentpositions, namely a convex position and a concave position. In thiscommon practice, when the bottom closure of the can has a concaveposition, as externally viewed, and when the cover is secured in place,this also has a concave position. After the can has been thus closed, itis commonly subjected to sterilization, this being achieved throughheating. During the sterilization, the pressure inside the can rises tosuch a degree that the two end closures are caused to assume their otherpositions, i.e. both end closures will become convex, as externallyviewed. When the sterilization has been completed, the can is allowed tocool to ambient temperature, and the two end closures resume suchpositions that they are both concave, as externally viewed.

For some time now, there has been a desire for a practice of fillingcans with hot goods, with subsequent sterilization of the filled cans.The same procedure as the one described above has then been applied asregards the end closures, as a precaution against an increase inpressure inside the can at the sterilization. However, difficulties havearisen when using cans with end closures arranged as previouslydescribed, as it has proved that at the cooling afiter the sterilizationa vacuum of such nature has been developed in the can that indentationsin the can body have resulted, owing to the fact that the air pressureexternally has been so great in relation to the pressure inside the can.In order to overcome this disadvantage, attempts have been made toprovide the can body with welts or beads encircling it, thus to make thebody of the can stronger. The use of heavier plate has also been tried.However, these measures have not proved to be entirely satisfactory andit has not always been possible to avoid indentations in the body of thecan.

The purpose of the present invention is to provide a can with endclosures constructed and arranged in such a way that, when the can isused for filling with hot goods which, after the can has been closed,are sterilized, the can, after or during the cooling, is not subjectedto body indentation caused by the difierence in pressure inside andoutside the can.

The problem is solved according to the present invention by using a canwhich has end closures, each of which can assume a convex or a concaveposition, externally viewed. According to the present invention, the canend closures are so constructed and arranged that when the can is filledwith hot goods, its bottom remains in a normal convex position, and thecover, after the filling, remains in a normal concave position. At thesterilization, the concave top or cover end closure will assume a convex3,400,853 Patented Sept. 10, 1968 position while the bottom retains itsconvex position. At the subsequent cooling, the two convex end closureswill assume concave positions, the change in position of one of the endclosures then compensating for the decrease in pressure arising owing tohot goods having been used for the filling.

With the above and other objects in view that will hereinafter appear,the nature ofthe invention will be more clearly understood by followingthe detailed description, the appended claims and the several viewsillustrated in the accompanying drawings.

In the drawings:

FIGURE 1 is a sectional perspective view illustrating a can and endclosures therefor according to the invention, the bottom and coverclosures being shown in their normal convex and concave position,respectively, the positions they normally hold in an unfilled butcovered can or in a closed can filled with hot goods or fill thereinprior to sterilization.

FIGURE 2 is a sectional View showing the closed can in the end closureconvex condition it assumes during sterilization, and

FIGURE 3 is a view siimlar to FIGURE 2 showing the end closures in theconcave positions they assume upon cooling of the sterilized fill anddevelopment of a vacuum in the can as a result of said cooling.

In the figures, 1 is a can body provided with two end closures 2 and 3,which have been folded on, that is, secured in place by the usualseaming operation, or otherwise. The can is filled with goods 4, whichcan consist of e.g. foodstuffs. The end closures 2 and 3 are so designedthat they can be caused to assume outwardly projected or convexpositions, or inwardly projected or concave positions by flexure of thecentrally located dished end panels thereof and as a consequence of thepressure conditions prevailing on either side of the end closuresinternally and externally of the can. The end closures are appropriatelymade of the usual metallurgical material. Furthermore, the end closuresshould have a thickness of between 0. and 0.4 mm.

According to the invention, when a can is empty and is to be filled, thebottom end closure 3 will be in its normal convex position. After thecan has been filled with hot goods, the end closure 2 is applied andsecured in position, which end closure then has its normal concaveposition, as shown in FIGURE 1. Thereafter the can is subjected tosterilization, which takes place through heating, and owing to theinternal pressure which then arises, the end closure 2 is displaced to aconvex position. FIG- URE 2 shows the end closure 2 of the can 1 in thisposition. When the sterilization has been completed, the can with itscontents is allowed to cool to ambient temperature, and the closure 2will then assume its concave position, Owing to the cessation of theincrease in pressure caused by the heat and expansion duringsterilization. Furthermore, the and closure 3 will also assume a concaveposition owing to the vacuum developed incidental to the temperaturedrop and contraction resulting from the cooling down of the hot goods orfill to ambient temperature.

Practical tests which have been carried out have shown that a can with adiameter of 129 mm., from the closing at the filling, has its volumeincreased by 57 ml. at the sterilization. When it has cooled, the volumeof the can has decreased by 78 ml. For a can with a diameter of 154 mm.the corresponding increase and decrease are and 405 ml., respectively,and for a can with a diameter of 218 mm., 360 and 1,000 ml.,respectively.

It is to be understood that the end closure 3 is designed to normallyassume a convex condition as shown in FIGURE 1 and not to partake of anysubstantial deflection or increase in convexity during the sterilizingaction, as depicted in FIGURE 2. This closure 3 is de- O signed,however, to be forced upward or into a concave position by atmosphericpressure when the can fill cools down to the ambient temperaturefollowing the sterilization process.

It is also to be understood that the cover or top end closure 2 isdesigned to be less resistant to pressure differential flexing than isthe end closure 3, thereby to substantially retain its normal concaveposition during hot goods filling and yet be subject to flexing outwardto the convex position shown in FIGURE 2 during the sterilizing actionand then to spring back to its initial concave position underatmospheric pressure action following cooling of the sterilized fill andupon development of a vacuum within the can as a result of said cooling.

From the foregoing, it will be apparent that by forming and arrangingthe two end closures in the manner herein described, the influence ofthe vacuum which develops owing to the can having been filled with hotgoods instead of col-d goods can be eliminated.

While a preferred package, packaging can structure and method of formingsaid package are disclosed herein, it is to be understood thatvariations in the can structure and package and the method steps may bemade without departing from the spirit and scope of the invention asdefined in the appended claims.

I claim:

1. A packaging can structure, intended for filling with hot goods, andafter filling and total closure, to be subjected to sterilizationthrough heating, and which in a closed condition consists of a tubularbody, an end closure for each end of the body, each said end closurehaving a dished, centrally located end panel means for providing the endclosures with the quality of assuming a convex or a concave position asviewed externally, said end closed structure being characterized in thatimmediately after having been closed after the filling with hot goods,it has one of said end panel means outwardly dished to provide a convexclosure and the other end panel means inwardly dished to provide aconcave closure, the said last mentioned one concave closure thenchanging from a concave position to a convex position at thesterilization and at a cooling following said sterilization to a not-hotcondition assuming a concave position.

2. A packaging can complement intended for the packaging of hot fill andwhich is to be subject to a sterilization processing following suchfilling and end closure sealing thereof, said can complement comprising,a body, a top end closure closing one end of the body and a bottom endclosure, closing the other end of the body, each said end closure havinga dished, centrally located end panel "means for providing the endclosure with the quality of assuming a convex or concave positiondepending upon differential pressure applications thereon internally andexternally of the can, the end panel means of one of said end closuresbeing normally outwardly dished, normally assuming a convex positionwhen the can is empty and when the can is filled with a hot fill, theend panel means of said other end closure being normally inwardlydished. said other end closure normally assuming a concave position whenthe can is empty and remaining in that position when the can is filledwith said hot fill but being subject to flexing to a convex positionduring a fill strilization heat application while said one can endclosure retains its convex poistion, and both said end closures beingsubject to flexing to concave positions upon cooling of the cansubsequent to completion of the sterilization heat application and as aresult of the creation of a vacuum within the can and application ofatmospheric pressure externally on said end closures.

3. A packaging can complement as defined in claim 2 wherein the top endclosure is the normally concave end closure.

4. A packaging can complement intended for the packaging of hot fill andwhich is to be subject to a sterilization processing following suchfilling and end closure sealing thereof, said can complement comprising,a body, a

top end closure closing one end of the body and a bottom end closureclosing the other end of the body, each said end closure having thequality of assuming a convex or concave position depending upondifferential pressure applications thereon internally and externally ofthe can, one said end closure having a lesser resistance to pressuredifferential flexing than the other end closure whereby it normallyassumes a convex position when the can is empty and when the can isfilled with a hot fill, while the other of said end closures normallyassumes a concave position when the can is filled with said hot fill butis subject to flexing to a convex position during a fill sterlizationheat application while said one can end closure retains its convexposition, and both said end closures are subject to flexing to concavepositions upon cooling of the can subsequent to completion of thesterilization heat application and as a result of the creation of avacuum within the can and application of atmospheric pressure externallyon said end closures.

5. A packaging can complement as defined in claim 4 wherein the endclosure having the lesser resistance to pressure diiferential flexing isthe top end closure.

6. The herein disclosed method of providing a sterilized hot goodsfilled package, said method comprising, providing a can complementincluding one attached end closure closing one end of the can and onecover end closure closing the other end of the can, each said endclosure having the quality of assuming a convex or concave positiondepending upon differential pressure applications thereon internally andexternally of the can, one said end closure normally assuming a convexposition when the can is empty and when the can is filled with a hotfill, the other of said end closures normally assuming a concaveposition when the can is empty and remaining in that position when thecan is filled with said hot fill but being subject to flexing to aconvex position during a fill sterilization heat application while saidone can end closure retains its convex position, and both said endclosures being subject to flexing to concave positions upon cooling ofthe can subsequent to completion of the sterilization heat applicationand as a result of the creation of a vacuum within the can andapplication of atmospheric pressure externally on said end closures,filling said can with the hot goods, securing the cover end closure onthe filled can, subjecting the filled and sealed can to a sterilizingaction by application of heat and thereby bringing about flexing of thecover end closure to its convex position, then upon completion of thesterilization action bringing about a cooling of the can to reduce thesame and its fill to ambient temperature and create a vacuum interiorlyof the can resulting in the flexing of both end closures to theirconcave positions.

7. A packaging can complement intended for the packaging of hot fill andwhich is to be subject to a sterilization process following the fillingand end closure sealing thereof; the can complement comprising a body, aflexible first end closure of normally concave configuration closing oneend of the body, a flexible second end closure-of normally convexconfiguration closing the other end of the body, said first end closurebeing more flexible than said second end closure, being responsive to arelatively high internal can complement pressure to flex outwardly intoa convex configuration during said sterilization process and beingresponsive to a reduction in internal can complement pressure to flexinwardly into a concave configuration upon cooling of said cancomplement following sterilization thereof, and said second end closurebeing responsive to relative low internal can complement pressure toflex inwardly into a concave configuration upon cooling of the fillbelow the hot filling temperature thereof.

8. A packaging can complement comprising a tubular body, normallyconcave first closure means for closing one end of said tubular body andresponsive to a first pressure condition within said can complement forflexing outwardly into a convex configuration and normally convex secondclosure means closing the other end of said tubular body and responsiveto a second pressure condition within said can complement for flexinginwardly into a concave configuration.

9. A packaging can complement according to claim 8 wherein said firstand second closure means comprise flexible first and second closuremembers respectively, said first closure member being more flexible thansaid second closure member.

10. A packaging can complement comprising a body, a normally concavefirst closure means, closing one end of the body responsive to a firstpressure condition within said can complement for flexing outwardly intoa convex configuration and responsive to a second pressure conditionwithin said can complement for flexing inwardly from said convexconfiguration to a concave configuration thereof, and normally convexsecond closure means closing the other end of said body, responsive to athird pressure condition within said can complement for flexing inwardlyinto a concave configuration.

11. A packaging can complement according to claim 10 wherein said firstand second closure means comprise flexible first and second closuremembers respectively, said first closure member being more flexible thansaid second closure member.

12. A packaging can complement intended for the packaging of hot filland which is to be subject to a relatively high temperaturesterilization process following the filling and end closure sealingthereof; the can complement comprising a body, a flexible normallyconcave first closure means closing one end of the body, for maintainingits concave configuration upon the enclosure of hot fill within said cancomplement, for flexing outwardly into a convex configuration upon thesterilization of said can complement, and for flexing inwardly from saidconvex configuration to a concave configuration upon the cooling of saidcan complement following sterilization, a flexible normally convexsecond closure means, closing the other end of the body, for maintainingits convex configuration upon the enclosure of hot fill and thesterilization of said can complement, and for flexing inwardly into aconcave configuration during cooling of said can complement followingsterilization thereof.

13. The method of providing a sterilized hot goods filled package, saidmethod comprising, providing a can complement including an attachedflexible end closure for one end of the can and a flexible cover endclosure for the other end of the can, filling the can with hot goods,securing the cover end closure on the filled can to form a filled andscaled can having one end closure of normally concave configuration andthe other end closure of normally convex configuration, sterilizing thefilled and sealed can so formed and the contents thereof by theapplication of a relatively high degree of heat thereto to cause theconcave end closure to flex outwardly to a convex configuration, andthen cooling the can and its contents to cause the outwardly flexednormally concave end closure and the normally convex end closure to flexinwardly to a concave configuration.

References Cited UNITED STATES PATENTS 1,570,732 1/ 1926 Emerson 220-11,963,795 6/1934 Lang 220-66 1,987,817 1/1935 Burns 220-66 2,027,430 1/1936 Hansen 220'-66 2,894,844 7/ 1959 Shakman 220 -6-6 3,105,765 10/1963Creegan 220--66 FOREIGN PATENTS 1,183,171 1/1959 France.

RAPHAEL H. SCHWARTZ, Primary Examiner.

